fix local dropping to not require extra locking of copies, but only that the local copy be locked for removal

Assistant/Unused.hs

@@ -77,7 +77,7 @@ expireUnused duration = do
 	forM_ oldkeys $ \k -> do
 		debug ["removing old unused key", key2file k]
 		liftAnnex $ do
-			lockContentExclusive k removeAnnex
+			lockContentForRemoval k removeAnnex
 			logStatus k InfoMissing
   where
 	boundry = durationToPOSIXTime <$> duration

Assistant/Upgrade.hs

@@ -97,7 +97,7 @@ startDistributionDownload d = go =<< liftIO . newVersionLocation d =<< liftIO ol
 		, transferKey = k
 		}
 	cleanup = liftAnnex $ do
-		lockContentExclusive k removeAnnex
+		lockContentForRemoval k removeAnnex
 		setUrlMissing webUUID k u
 		logStatus k InfoMissing